[GRASS-user] [GRASSLIST:1154] Re: rectifying vectors

[Hamish]

Kirk Wythers wrote:

> I have moved a series of dxf files into grass with the new v.in.dxf.  
> However, I have discovered that the original dxf files were not  
> georectified. They came from some sort of xy location system. I have  
> been thinking about ways to rectify the grass vectors I created. The  
> only ideas I have come up with would involve writing the new grass  
> vectors out with v.out.ascii, developing a "correction factor",  
> applying the correction to the ascii files, then reading the ascii  
> files back into grass with v.in.ascii.
> 
> Does anyone know of less cumbersome approach?


Hi Kirk,

It is typical for DXF data to be unprojected. Use v.transform.

for something more interactive you might try some mix of {v.to.rast +
i.vpoints + analyze the group/POINTS file} to get the v.transform
parameters, or try Michael's new GeoRectifing tool (gis.m
File->GeoRectify)?



Hamish